When he orders the Enterprise-D to divert to Dytallix B, Riker asks Picard if they should let Pacifica know they will be late, and Picard says "Negative. Nothing goes out without specific orders from me." A few (screen) minutes later, they arrive and find three other starships in orbit. Worf says "Attempts at communication have been ignored by all three vessels." So... why has Worf made attempts to communicate with the three ships when Picard has already expressly stated that they are to send no messages out to anybody without his specific orders? Bad Worf!

These alien parasites make you immune to phasers by flooding your body with adrenaline. How does adrenaline stop you getting a hole drilled in your chest?

I have to say, it's so common in science fiction that it's practically a cliche, but why the hell does killing the queen alien kill all the others? Even assuming some sort of telepathic link between them that made such a thing even possible, can you imagine such a bizzare weakness evolving in a species in the first place? Admittedly given the non-canon explanation for the creature's origins this becomes a bit more plausible, but taking the episode at face value it is a serious weak spot, an obvious way to try and wrap up the whole conspiracy in a line or two of dialogue.

In his closing log, Picard notes that Quinn is recovering since his parasite died when the Queen was killed. He states that they may never know how far the infestation went. Um, what? Won't everyone who was infested now wake up and tell everyone what they did whilst under control? Or even if we assume that you don't remember anything that happened whilst you were controlled, you'd still have a list of every infected person. So you'd quickly know exactly how far the infection had gone, right?

Great Moment :

Remmick's death, amazingly gory for Star Trek!

Body Count :

The crew of the USS Horatio, plus Remmick and the slug inside him and the other little parasites.

Factoid :

This is the first episode that Picard ever orders "tea, earl grey, hot"!

When first shown in the UK, the gory death of Remmick was cut. This is one of only two episodes ever censored by the BBC (the other being a deleted reference to the reunification of Ireland in "The High Ground")

The "Star Trek : The Next Generation Companion" states that the homing signal would bring the Borg to Federation space. At this stage the Borg were an insect race who used the parasites as their first wave. The idea was dropped for budgetary reasons.

The Deep Space Nine novel "Worlds of Star Trek: Deep Space Nine, Volume 2, Trill & Bajor" reveals that the alien parasites are genetically modified versions of the Trill symbionts! A deadly plague had been destroying the symbionts, and experiments were made to try and find a cure. The modifications created symbionts who were violent and xenophobic.

The computer interrupts Data when he tries to explain something to it, saying "Thank you sir, I comprehend." This is the only instance in all of Star Trek to a ship's main computer referring to itself in the first person.

This is the first episode of Next Generation to feature Earth.

It's also the first episode ever to feature a Bolian, Captain Rixx.

The large Star Chart seen on the wall behind Remmick features many planets mentioned in the Original Series and Animated Series.

Plotline

The Enterprise-D is en route to Pacifica when Picard receives a code 47 message from Walker Keel, an old friend and Captain of the USS Horatio. The message directs Picard to a rendezvous on Dytallix B, an abandoned mining colony, and urger the greatest secrecy and discretion. Picard meets with Walker and two other Captains, the Bolian Rixx and the Human Tryla Scott. They grill Picard about his past before revealing that they believe some sort of conspiracy is afoot within Starfleet. There is a pattern of mysterious orders reaching the highest levels of Starfleet Command. All they know is that those affected seem to have some peculiar problem with memory. Picard is unconvinced, but returns to the Enterprise and orders Data to analyse all Starfleet orders over the last six months. As Data works the ship finds evidence of an explosion; wreckage of the USS Horatio is found drifting in space. Concerned with his friend's untimely and suspicious death Picard reveals the conspiracy to Riker. Data arrives and reveals that there is indeed a pattern of unusual orders; most especially reshuffling of personnel in the command areas. He theorises that the orders are an attempt to gain control of key sectors of the Federation.

Picard decides to return to Earth itself. On arrival the ship is contacted by Starfleet command and Picard is invited down to discuss his concerns with several Admirals. His old friend Admiral Quinn cannot attend the dinner but asks if he can have a tour of the Enterprise, a request Picard grants. When he arrives Picard questions him about the mysterious threat to the Federation Quinn referred to the last time they spoke but the Admiral brushes it off, claimind he only meant the problem of intergrating new members as they joined. Realising that this is some sort of impostor, Picard tells Riker to keep an eye on him after he beams down.

In his guest quarters Quinn shows Riker an small alien life form he has brought with him, claiming it is a totally superior form of life. He attacks Riker, stunning the First Officer with his amazing strength. Quinn tries to fight his way past security when they arrive, and is almost successful - but is disabled by repeated phaser blasts from Crusher. In sickbay she examines him and finds a small appendage sticking out of the back of his neck.

At Starfleet the Admirals try to convince Picard that there is no great conspiracy, but he is able to contact the ship and Crusher reveals that Quinn has been infested with some sort of parasite. She tells him that stun has little effect on the affected people, and he must set his phaser to kill instead of stun. Picard, however, is unarmed. When he goes in to dinner he is disgusted to find that the food is living worms and realises that everybody there is infected. Riker arrives, having apparently been infected by the parasites. As the Admirals congratulate themselves on gaining control of the Enterprise Riker pulls a phaser and starts shooting; he was only pretending to be infested. Picard and Riker chase one of the parasites into a room where they find Dexter Remmick sitting. He swallows the parasite calmly, asking Picard and Riker if they have a problem. They fire on him, blasting half of his body away and revealing a "queen" parasite inside. Disgusted at the creature, they destroy it with another blast.

The death of the queen kills all the other parasites, freeing the infested officers and ending the conspiracy. However, analysis reveals that Remmick sent a signal before his death - a homing beacon, directed out into space far beyond the Federation...

Analysis

A pretty good episode, this one. Although being taken over by aliens harks back a long way in science fiction (Heinlein's "The Puppet Masters" is the earliest I know of), this episode plays it quite well for the most part. A few things stand out as being a bit silly; the aliens themselves are not very convincingly done, with their movements looking rather unconvincing - stop-motion animation if I am not mistaken, and not terribly well done. As mentioned, the idea that they can produce massive amounts of adrenaline and so make people phaser proof is a bit absurd, and the idea of killing the queen to kill them all is a bit farfetched. But overall, the idea of Starfleet being infiltrated this way works reasonably well.

It's nice to see the Enterprise back at Earth, though it seems to get there awfully fast. True no timeframe is given and for all we know it took weeks or months for the trip, but it sure doesn't seem like that's the case.